Integral casing packing seat



Sept. 15, 1959 M. c. TURNER INTEGRAL CASING PACKING SEAT Filed 061'.. 21, 1954 Mmm.

o o o u n a MJP- United States Patent'v INTEGRAL CASINGPACKING'SEA'I" Y Marshall C. Turner, Bartlesville, Okla, assignor to Phili This invention relates to improved apparatus for use in producing a well. A speciiicaspect of the invention .pertains-to combination collarsand packers for well casing and tubing.

The cost of drilling and completing oil and gas wells can be reduced it the size of the borehole is reduced. For example, the cost of casing and cement and the cost of drilling obviously a-re less with small holes than with larger ones; However, tok allow the installation lof necessary equipment and to facilitate the downhole operation of equipmentV it is desirable to have the wells as large as possible. Thus,v in most instances, the well size is a compromise between what is desirable and what is economical.

Obviously then, it is important to use the available space in a well bore efficiently. This becomes particularya 2,904,115 [ce Patented Selt- 15 1959 which is attached to the collar and must necessarily be smaller in inner diameter than any'casing `joint yin the Istring.- so as to permitpassage thru the string of a tubing vcollar` which ts the inner wall of the casing ,collar and forms a, seal therewith. When running the casing in the well aspecial casing collar is inserted in the casing string at the desired point so as to provide packing off between the casing and tubing. Where more than one pack-oil? is' desiredorrequired, additional special casing collars are inserted attherequired locations in the casing string as it v'is vbeing run.r The invention also provides tubing collars or connectors which form a seal with the special casing collars and which have a plurality of conduits 'running therethru to provide for a plurality of tubing strings t0. meet the requirements of multiple zone production-in a'well.

For al more complete understanding of the invention reference may `be had to .the drawing of which Figure 1 is an elevation, partly in section, of the casing collar and cooperating tubing collar or Vconnector in combination with well casing andv tubing; Figure 2 is an elevation,

ly true when the well is a dual completionin which-it e f is necessary to, separate the production from two zones. In the' latter instance,I and lin a flarge number of single completions, it is necessary or desirable to use one or more packers. An ordinary packer takes up a greatrdeal of the .cross sectional area of; a well. A packer generally combines means such as tapered slips, to hold; it in place in the well, and means to seal between the. packer body and the casing and between the packer body and the tubing. These parts take upsov much of the available area in the well that, with one popular packer, the largest diameter tubing` that can be run thru the packer in a 5% in. casing is 1.900 in. O.D. plainv tubing or 2.375-in O.D. ush joint tubing. In 7' in. casing it is possible -to run 2.375 in. O D. plain tubing or 2.875 in O.D.ruish joint tubing.

Through the use of the invention, space in a well` is utilized` much more eliiciently thus making it possible to run a much larger string oftubing in any1-given casing or to run a plurality of ordinary tubing strings therein.

An` object ofthe invention isr toA provide improvedy wellproducing apparatus. `Another object is to provide improved well producing apparatus whicheects an economy of space in a well and permits use of smaller bore holes or the use of a larger number of pipes or larger pipes in a given borehole. A further object of the invention is to provide a simple and, etlicient combination casing collar or pipe connector and packer which eliminates need for a special packer. A further object is to provide' novel' pipe collars forwell casing and tubing which cooperate to function as packers. of the invention is to provide apparatus 'which .simplifies `producing from multiple zones in a well. Other objects of the inventionY will become apparent from a con,- sideration of the accompanying disclosure. y l

The invention utilizes a novel casing colla-rwhich provides a seat onits inner wall for a cooperating tubing collar having sealing means, thereon, thereby eliminating ther need forl a'special or separatepacking device in order to 'seal oft ow in.V the annulus surrounding the tubing Another object is of lesser diameter than the inner diameter of the casing `partly in section, of a casmg string 'and a plurality of tubing strings connected by the novel collars or connectors ot the invention; Figure 3 is a longitudinal view in partial Section of a vtubing collar; Figure 4 is a longitudinal` view, lirl partial section of another modification or embodiment ofthe t-ubingcolla'r'of `the invention; Figure 5 is a plan view ofa multiple-tubing connector, and Figure- 6 ,i s a` sectional View taken on the line 6-6 o f Figure 5. The various figures of the drawing are schematic vand corresponding parts are lcorrespondingly numbered.

Referring to Figure 1:, at any point where it'is desired toA /providea' packer the regular casing collar connecting joints a and b ofV casing string 10 is replaced by special collar- 1-1which has a body portion 1-2` and` threaded end sections 13 and 14. The inner wall -16 of body portion 12;.ofjcollar 1,1 is machined or otherwise providedwith a Atrueyand regular surface so as to form a seat for tubing collar 18. The inner diameter of body member 12 is sufliciently smaller than, the inner diameter of threaded end sections 13 and; 14k to` accommodate casing joints a and b oflarger internal diameter than body member 12 soy as to permit the free movement of tubing collar; 18 thru the casing string until it reachesk the special collar A1-1 and seat 16 thereof.

In operation, after the casing string containing collar 11 has been run and cemented in a well the tubing string 21 including collar-18 having seal rings 22 embedded in its outer wall is run and brought into position as shown in Figure l. As collar le'enters collar 1-1, seal rings22 cooperate with the inner wall or seat 16 of collar 11 to provide la seal or pack-off preventing upwardA or downward` migration ofithe fluids in the annular space 23 between the casing and tubing past; collar 11.

Although not illustrated, it is possible and may be desirable in some instances to provide collar 11 with a shoulder lwhich is engaged by a mating shoulder on the upper end of collar 18 to eliminate the necessity of making'fvery accurate measurements to locate collar 18 relative to collar 11 and also to permit collar 11 to support a portion` of the weight of the tubing string. In instances where itis desired to place the tubing 'string in tension; collars 11 and 18V are provided with a suitable latching mechanism, to permit these `members to be detachably engaged; Baker Oil Tools, Inc., of Los Angeles, Cali,- fornia, show in its 1954 catalog at pages 501 to 503. a tubing sealv locator sub and a latching sub which may be utilized-as the devices just referred to. Figure 2 `showsj anV arrangement wherein a, pair 'of collars 11 and 11 arerun' in` casngstringlllV to permit separation of zones 26 and 27. A tubing collar or con- 11. These may be run parallel to tubing strings 32 and "31 or concentric with either or both of these. l Additional tubingv strings are utilized in producing multiple zones in a-well and in separately producingoil and gas in dual production zone wells. l

`QCollars 11v and 11 are similar in-construction and design Vto-collar 11 of Figure l. The internal diameter of-collar 11v preferably is slightly smaller than that of 'collar-11' but it is also feasible to mnY the tubing strings Lorf Figure `2 when the internal diameter ofl collars 11l and 111'" vare equal. Although collars 11 and 11 are illustrated with regular collar threads it may be desirable in some instances to provide pin and box threads to eliminate the necessity for removing a casing collar; and it is also feasibleto weld these collars in the casing string. Obviously vcollars or tubing connectors 29 and 34 can be provided with connections'for any desired number of tubing strings -of the same or different diameters. These collars comprise ya cylindrical body member having seal rings 22 embedded in the outer wall thereof similar to those of collar 18. A suitable number of conduits extend longitudinally thru the cylindrical body and have suitable means for attaching the tubing such as a threaded end section in each conduit into which the tubing is threaded. If desired, collars 29 and 34 may be identical in which case threaded plugs, not shown, are screwed into the openings in collar 34 which are not to be used.

lAlthough the inside diameter of collars 11 and 11 can be varied from wcll to well to suit specific conditions, if desired, it is preferable to standardize these collars and to use such standardized collars when possible. In gen eral it can be stated that the inside diameter of the collar Y should be somewhat smaller than the inside diameter of the heaviest pipe with which it is to be used in order to permit free passage of collars 18, 29, and 34 thru the casing, but not -small enough to prevent passage of cementing plugs therethru.

Figure 3 shows an embodiment of the tubing collar 18 in which the outer wall of the cylinder is provided with grooves 36 in order to recess O-rings 22. Threads 38 at each end on the inner wall of the collar provide attaching Vmeans for the tubing joints -at either end.

Figure 4 shows an embodiment of collar 18 in which a ange 39 is provided at one end of the collar as a shoulder for spacers 40fand packing or seal rings 41. A locking ring 42 screws onto the end of the collar to provide compression on the seal rings and spacers, Any suitable seal 'rings may be utilized in the collars of Figures 3 and '4. Y

Figure 5 shows a plan view` of a tubing collar or connector, such as 29, providing three different connections for as many tubing strings. As illustrated in this figure, conduits 43 and 44 are of similar diameter and conduit 45 is of larger diameter.

Figure 6 is a cross section of the tubing collar of Figure 5 taken on the line 6--6 and shows threaded sections on the ends of conduits 43 and 45 for attaching to well tubing or other conduits.

The apparatus of the invention eliminates much of the complicated mechanism utilized in conventional equipment for sealing olf between the tubing and casing of a well and provides an efficient sealing means which occupies considerably less lateral annular space than does equipment heretofore available. l

Certain modifications of the invention will become apparent to those skilled in the art and the illustrative de tails disclosed are not to be construedl as imposing unnecessary limitations on the invention. l

I claim:

1. A pipe connector-sealing member comprising a cylindrical body the outer surface of which is a substantially continuous cylinder having sealing rings spaced apart thereon isaid body including a plurality of conduits running therethrough parallel with the axis thereof; and means in said body at each end of each of said conduits for forming a joint with a pipe.

2. The device of claim l wherein said means comprises I a threaded section on each end of each conduit.

3. In combination in a well bore, a string of pipe connected by at least one pipe collar having internally threaded end sections threaded .to said pipe and an intermediate body section of smooth cylindrical bore of lesser diameter than the internal diameter of said pipe providing a sealing surface; a plurality of pipe strings within said string of pipe connected at said pipe collar by means of a pipe connector-sealing member comprising a cylindrical body the outer surface of which is a substantially uniform cylinder slidable completely thru said pipe'collar; sealing rings on said pipe connector-sealing member forming a seal with said sealing surface; and in said body a plurality of conduits running therethrough parallel with itsaxis, each conduit being axially aligned with one of said strings of pipe.

4. The apparatus of claim 3 including a second pipe collar of the character described positioned in first said pipe string below aforesaid pipe collar; a second pipe connector-sealing member of the character described positioned inside of said second pipe collar to form a seal therewith; and at least one pipe string connected to both said pipe connector-sealing members to provide a passageway for uids fromazone below said second pipe collar upwardly thru last said pipe string to a zone above rst said pipe collar.

5. The apparatus of claim 4 wherein said second pipe collar is of lesser inside diameter than rst said pipe collar.

6. The apparatus of claim 4 including a pipe string eX- tending-from a position between saidfconnector-sealing membersupwardly thru the upper of said members to a zone above same.

7. In combination a rst pipe string connected by pipe collars having internally threaded ends, each of said collars having a smooth internal bore of uniform diameter substantially smaller than the internal diameter of said pipe string; a second pipe string connected by pipe collars internally threaded at each end and of uniform external diameter slightly less than said bore; sealing rings on said second pipe collars lwhich form a seal between same and the outer pipe collars when the inner collars are positioned within said rst pipe collars, said second pipe collars with seal rings thereon being slidable completely thru said first pipe collars to permit lowering said second string of pipe Within said 'rst string thru successive such rst pipe collars in said first string and positioning said second pipe collars in sealed relation with said rst pipe collars.

8. The combination of claim 7 wherein a pair of said collars form a seal between said strings of pipe above an upper producing formation and a second pair of said collars form a seal between said strings above a lower producing formation; said outer string is perforate adjacent each of the formations; and said inner string terminates at substantially the level of said lower formation.

9. The combinationof claim 8 including a third string of pipe extending thru the inner collar of the upper pair and terminating intermediate the upper and lower pairs of collars.

10. In vcombination a pipe collar adapted to couple a pipe string, comprising an elongated annular member havinginternally threaded end sections adapted to thread over the end of matching pipe and a body section intermediate said end sections of smooth uniform internal bore extending Y, cpmpletely thru said body section, said bore being of substantially lesser diameter than the internal diameter of said end sections to provide a cylindrical sealing surface; a pipe connector-sealing member comprising a cylindrical body having a uniform cylindrical outer surface provided with seal rings forming a seal with said cylindrical sealing surface, said member being slidable completely thru said collar; and at least one conduit extending longitudinally thru said cylindrical body.

References Cited in the le of this patent UNITED STATES PATENTS Harold Aug. 8, 1876 Yerkes et al Mar. 31, 1931 Otis May 9, 1950 Rhoades Aug. 5, 1952 Clifford Ir. Mar. 1, 1955 

